Automatic alarm for steam-boilers.



Patented July 18, 1899.

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- A. M. PRENCEL.

AUTOMATICALARM FOR STEAM BOILERS.

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(Applicntion filed Sept. 7, 1898.;

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UNITED STATES.

P TENT OFFICE.

ANTHONY M. "PRENCE'L, or sEeUIN, TEXAS.

AUTOMATIC ALARM FOR STEAM-BOILERS.

SPECIFICATION forming part of Trotters Patent No. 629,206, dated July 18, 1899.

" Application filed September '7, 1898. Serial No. 690,436. (No model.)

- T (LZZ whomtt may concern: I

Be it known that I, ANTHONY M. PRENOEL, a citizen of the United States, residing at Seguin, in the county of Guadalupe and State of Texas, have invented a new and useful Automatic Alarm for Steam-Boilers, of which the following is a specification.

This invention relates to automaticalarms. for steam-boilers 5 and the object of the inven tion is to provide an improved alarm of this class which shall be simple in construction and relit his in operation adapted to be connected with steam-boilers of any form or construction or the reservoirs for containing other fluids under pressure andto be operated whenever the pressure within the boiler or reservoir reaches a point previously fixed by adjustment.

"With this object in view the invention consists in the improved construction,arrangement, and combination of the parts of an automatic boiler alarm mechanism which will be first fully described hereinafter and afterward specific'ally pointed out in the appended c1aims.

In order to enable others skilled in the art to which my invention most nearly appertains to'm'ake and use the same, I will nowproceed to describe its construction and operation,

having referenceto the accompanying drawings, forming part of this specification, in

whichi Figure l is a view, partly in elevation and partly in section, illustratingmy invention applied to the dome of a steam-boiler. Fig. 2 is a detail vertical sectional view on vthe dotted line 2 2 of Fig. 4, looking to the left,

as indicated by the arrows. flFig, 3 is 'a s imi-' lar View on the. dotted line 3 3 of Fig. i, look; ing to the right, as indicated by the arrows; Fig. 4: is a view'in end elevation of the mech-' anism for operating the alarm-bell removed from the case.

view in elevation with the stop-pawl broken 5 away. Fig. 6 is adetailview'of the gage.

Referring to the drawings by numerals, 5 indicates in this instance a steam-boiler, al-

though it may be. any reservoir containing Fig. 5 is a fragmentary detail 8 indicates a cylinder threaded upon the upper end ofthe pipe 7, provided with'a projecting ring 9, shaped to receive a wrench for turning it. The cylinder 8 is screw-threaded interiorly at itsupper extremity and provided near itslower extremity with an inwardly-projecting annularfiange 10.

11 indicates a sleeve provided with exterior 6o threads,wherebyit may be'threaded into the upper end of the cylinder 8, and with an outwardly-projecting annular flange 12, to which are secured upright brackets 13 to support a casingla to contain the bell-ringing meohanism.

15 indicates a disk or piston-head fitted steam-tight in thecylinder 8. above the flange 10. V v 16 indicates a disk fitted to slide in the'cylinder 8 above the disk 15. t v

.17 indicates a screw-plug threaded into the flange 12 of the sleeve 11 and projecting be yond the'slee've for some distance downward into the cylinder 8. The disks 15 and 16 and i the screwthreaded plug 17 are each provided with central perforations in vertical alinement with each; other, and a rod 18 passes downward through these central openings, the lower end of the rod being screw-threaded So where it passes through the disk 15 and provided with nutsf19 and 20 below and above said disk, respectively, whereby the rod-and disk are rigidly secured together. A spring 21 is coiled about the rod 18'between the disks 15 and 16, and the upper end' of the rodis provided with as'uitable-seat to receivethe lower end of a rod 22 of the bell-ringing mechanism.

' 15 indicates set-screws to limit the upward movement of the piston 15 and prevent break age by sudden upward movement. 1' The plug 17 being screw-threadedin'to the sleeve 11 is consequently adjustable therein,

and such adjustment is regulated'according to a graduated scale on a metal bar 23, piv- 5 oted'to a second metal bar 24, secured in position by a screw-bolt 25, which, with a similar screw-bolt 2 6, secures the sleeve 11 and brackets 13 together. 7

The'bell-ringing or alarm-sounding mechanism is mounted in two metal frames 27 and 28, whichare secured together by cross-pins 29, 30, 31, and 32, the whole mechanism being j somewhat similar to the striking mechanism of a clock. Mounted in the frames 27 and 28 is a shaft 33, to which is secured the inner end of a coiled spring 34, the outer end of which is secured to the cross-bar 29. A gearwheel 35 is loosely mounted on the shaft 33 and is provided with a pawl 36, adapted to engage in one direction the teeth of a ratchetwheel 37, secured upon said shaft, the pawl being held in contact with the ratchet-wheel by means of a spring 38, secured to the gearwheel 35. The gear-wheel 35 is provided with a series of laterally-projecting pins 39, and in the path of these pins is pivoted an arm 40, projecting from the cross-bar 30, which acts as a rock-shaft and carriesan arm-upon the outer end of which is secured a clapper 41, adapted to strike a gong 42, secured upon the mechanism-frame back of the rod 22, the clapper -ar1n being spring -actuated. The gear-wheel 35 meshes with a pinion 43, secured upon a shaft 44, upon which is also secured a disk 45, having a notch 46 at one edge, the circumference of the disk being cut away slightlyon each under side of the notch. A gear-wheel 47 is also secured upon the shaft 44 and meshes with a pinion 48 on a shaft 49, which carries a fan 50 to govern the speed at which the shaft is rotated.

On the disk 47 is a pin 51, projecting laterally therefrom near the shaft 44, which pin at every revolution of the disk moves a wheel 52, provided with teeth 53, the distance of one tooth. The .wheel 52 is loosely mounted on the shaft 53 and bears against the frame 28 with sufficient'friction to prevent it from moving loosely on the shaft, but to permit it to be moved independently of the shaft when desired. This wheel is further provided with a series of deep radial notches 54 of any desired number and at equal distances apart, there being eleven illustrated in this instance, separating the circu mference into eleven sections with six of the teeth 53 in each section. The pin 31 before referred to performs the function of a rock-shaft, and upon it are mounted a pawl 55, having down ward-bent outer end 56, and a pawl 57, having laterally-bent outer end 58. The rod 22 is pivotally secured to the pawl 55.

A petcock 59 is secured in an opening in the cylinder 8 in line with the disk 15 and closed by said disk when the disk is seated 011 the flange 10.

The operation of my invention may be described as follows: It, being desiredthat the engineer shouldbe notified when the pressure in the boiler goes above a certain number of pounds to the square inch, the plug 1.7 is turned to bring its upper edge opposite the figure 120 on the gage, which will indicate that the spring 21 has been compressed sufliciently to counterbalance a pressure of one hundred and twenty pounds. Then the petcock 59 is left open and no steam escapes therefrom, it indicates that the disk 15 is on its seat-namely, the flange lO-and when an ordinary steam-gage is used in addition to the alarm mechanism the pressure indicated on the steam-gage should .be the same; as that indicated on the scale 23. In order to test the accuracy of this agreement of the two devices, the petcock may be opened when the pressure indicated on the scale 23 is lowerthan that indicated on the steamgage, which of course will permit steam to escape. Leaving the petc'ock-open, the scre\ plug is screwed down until it cuts off the escaping steam, which will only be done when the disk 15 is forced into-its seat on the flange 10. The pressure indicated on the gage 23 should now agree with that on the regular steam-gage. With the alarm set at 120, as before statechany higher pressure within the boiler will force the disk 15 outward, carrying the bar 18 and the rod 22 with it, raising the I pawl 55 out of the notch 54 and the pawl 57 out of the notch 46, leaving the alarm mechanism free to operate. The alarm mechan-- ism being actuated by the spring 34 will continue to operate and cause the clapper 41 to strike the gong 42 each time a pin 39 actuates the lever 40, said lever dropping upon the next securing-pin 39 and permitting of the movement of the rock-shaft 30 and clapper 41. As long as pressure isinaintained above 120 the pawls will be held out of their notches and the alarm continue to ring; but as soon as the pressure is d ecr'eased sufficiently to permit the spring 21 to force the disk 15 down to-its seat the bar 17 and rod 22 will drop with it, permitting the pawls 55 and 57 to drop into their notches, and thus stop the operation of the alarm. Upon abnormal pressure being caused in the boiler or reservoir the disk 15 will become unseated and travel upward, thus imparting an upward movement to the rod 22 through the medium of the rod 18. The rod22 thus releases the pawls 55 and 57 from contact with the notches 54 and 46, respectively, and thus operates the bell-clapper. The multiplicity of the laterally-projecting pins 39 will give a vibratory motion to the clapper, which will last until the mechanism runs down or the pressure is taken off or removed. The disk 15 will then assume its normal position, being seated upon the flange 10 of the tube 8, and allow the pawls 55 and 57 to drop into their notches, when the alarm will again be ready for use. It is of course obvious that the movement of the disk 15 can be limited by the set-screws 15.

The advantages attending the use of my invention will be obvious from the foregoing description, the operation of the alarm being automatic and any excess of pressure being instantly called to the attention of the engineer.

The invention may be used on a boiler supplied with the ordinary steam-gage or may be made to take the place of the ordinary steam-gage, the adjustments of the various parts being easily performed and the arrangement being such that it is impossible for the pressure in the boiler to increase beyond the predetermined height without notification to the engineer.

While I have illustrated and described the best means now known to me for carrying out my invention, 1' do not wish to be understood as restricting myself to the, exact details of construction shown, but hold that any slight variation therefrom, such as might suggest itself to the ordinary mechanic,would be clearly comprehended within the limit and scope of my invention.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is-

1. The combination with a steam-boiler, of a cylinder communicating with the interior of the boiler and provided with an interior annular flange, a disk fitted steam-tight in the cylinder adapted to be seated on said flange, a spring outside of the disk arranged to press the disk inward against the pressure of the steam, a second disk loosely fitted in the cylinder, a sleeve threaded in the outer end of the cylinder, a screw-plug projecting into the cylinder and threaded into the sleeve the lower end of which is adapted to bear against the upper face of the second disk to regulate the tension of the spring, an alarm mechanism, a bar secured to and moving with the disk, passing through the second disk and the screw-plug and adapted to operate the alarm mechanism, when the pressure in the boiler is suflicient to overcome the pressure of the spring, and agraduated bar mounted alongside of the screw-plug, substantially as described.-

2. The combination with a steam-boiler, of a cylinder communicating with the interior thereof and provided with an interior annular flange, a steam-tight-fitting disk in the 40 cylinder and adapted to be seated on said flange, an upwardly-projecting rod mounted on said disk and adapted to operate an alarm mechanism secured to the top of the cylinder, a second disk loosely fitted in said cylinder and adapted to'be adj ustably pressed uponan intermediate spring, by means of a screw-plug projecting into the cylinder and threaded into a removable sleeve substantially as described.

3. The combination with a steam-boiler, of a cylinder communicating with the interior thereof, a sleeve threaded into the outer end of-the cylinder and provided with a circumferentialfla'nge, brackets secured to the flange 5 5 of the sleeve, a casing mounted upon the brackets and carrying an alarm mechanism provided with a downwardly-depending starting-rod, an inwardly-spring-pressed, steamtight, disk in the cylinder, and a bar secured 6o thereto and adapted to operate the startingrod of the alarm mechanism when the disk is pressed outward against the spring by excess of pressure, substantially as described.

' ANTHONY M. PRENCEL.

Witnesses:

A. E. WILSON, J r., J. W. Evans. 

